Feasibility Study of Enhancing Microwave Brain Imaging Using Metamaterials

Abstract

We present an approach to enhance microwave brain imaging with an innovative metamaterial (MM) planar design based on a cross-shaped split-ring resonator (SRR-CS). The proposed metasurface is incorporated in different setups, and its interaction with EM waves is studied both experimentally and by using CST Microwave Studio® and is compared to a “no MM” case scenario. We show that the MM can enhance the penetration of the transmitted signals into the human head when placed in contact with skin tissue, acting as an impedance-matching layer. In addition, we show that the MM can improve the transceivers’ ability to detect useful “weak” signals when incorporated in a headband scanner for brain imaging by increasing the signal difference from a blood-like dielectric target introduced into the brain volume. Our results suggest that the proposed MM film can be a powerful hardware advance towards the development of scanners for brain haemorrhage detection and monitoring.

Image Improvement Through Metamaterial Technology for Brain Stroke Detection

“…The metallic pattern (thickness = 0.10 mm) is a variation of the Jerusalem Cross SRR. Our previous studies have already shown the MM unit cell design and the performance of MM layers based on this structure [13], [14].…”

Metasurface-Enhanced Antennas for Microwave Brain Imaging

“…These two high dielectric substrates are bonded with with Rogers 3001 bonding film ( = 2.28, tan = 0.003). In previous work [ 18 , 34 ], we have performed several simulation studies to optimize this geometry for operating in contact with the human skin when immersed in our coupling medium.…”

“…To test the performance of our new PSMA and MTS-enhanced PSMA operating in air, we compared our previous developed brain scanner operating in an infinite lossy matching medium to two tomographic systems: an 8-PSMA system and an 8-MTS-enhanced PSMA system. Our previous developed MWT scanner for brain imaging consists of 12 spear patch antennas immersed in a 90% glycerol-water mixture and placed around EN 50361 Specific Anthropomorphic Mannequin (SAM) head model [ 18 , 19 ]. A similar setup (“System 1”), including 8 antennas placed elliptically around our numerical head model, was modelled in CST Microwave Studio.…”

“…To couple the transmitted power into the body and improve the detection of useful scattered “weak” signals, we could take advantage of metasurface (MTS) technology. As demonstrated in our previous studies [ 18 , 19 ], one way to improve the efficacy of a MWT system is incorporating MTS structures into its array, adjacent to the substrate of each antenna. Using this hardware configuration, we have obtained higher quality reconstructed images of a blood-mimicking target placed inside the brain volume of our numerical head model.…”

Feasibility Study on Improving Microwave Stroke Detection using Metamaterials

“…In addition, MM structures can be used to couple the incident power into the brain tissue. To this end, our previous studies have shown that tailored MM designs might be a powerful advance towards the development of MWT scanners [6]. This paper examines the potential of improving the quality of the reconstructed images by integrating MM technology in our radar-based imaging scanner.…”